捕食线虫性真菌的分离培养及分布规律

对自然界中的捕食线虫性真菌进行了分离和种属区分，并对分布规律进行了研究。从土壤、粪便等材料中获得了2类活性较强的捕食线虫性菌株：即套捕型(hooping)捕食线虫性真菌和粘捕型(sticking)捕食线虫性真菌。主要的代表种类有3种。这些捕食线虫性真菌在捕食性结构分生孢子形态及某些生物学特性上有一定差异。套捕型捕食线虫性真菌代表种为少孢节丛孢菌(Arthrobotrys oligospara)和梨形指环菌(Dactylaria pyriformis)，它们以菌环、菌网作为捕食性结构(器官)，以套捕方式杀灭线虫幼虫。梨形指环菌可产生多量厚垣孢子(chlamyalospore)。粘捕型捕食线虫性真菌代表种为纺锤隔指孢菌(Dactylella ellipsospora)。可形成菌结捕食线虫性结构，以粘捕的方式杀灭线虫幼虫。结果表明：捕食线虫性真菌在土壤和家畜粪便中的分离率是40．41％；此类菌适合于生存在阴暗、潮湿、富含腐植质的环境中。在温暖季节时，采用0．4g／L玉米粉琼脂培养基(CMA)易于对其进行分离培养。     

白浆土的氮素分布特征

本文以黑龙江省三江平原耕地白浆土为主要研究对象,并以复区内存在的草甸土和暗棕壤作比较,研究了土壤各种理化性质与不同形态氮素之间的相关关系:白浆土中 HA 和 FA 的主要差别,在于前者含有较多的碱性氨基酸,而后者则含有较多的酸性氨基酸;各种不同形状 N素与土壤 pH 值,质地等相关性不显著,而与土壤有机质、全 N 和 C/N 比值等的相关性极为显著。     

长沙-株洲-湘潭-体化中道路交通发展目标初探

在提出长株潭道路交通总体规划设想的前提下,分析长沙市路网,提出道路交通发展目标.     

Acoustic evaluation of the vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in Lake Biwa

SUMMARY: The vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in the pelagic waters of Lake Biwa was evaluated from June to September in 1995–97 from eight acoustic surveys using a quantitative echosounder. In each survey, echoes from a depth range of 3 m to the sea bottom were collected at a station every 2.7 s for 24 h together with measurements of vertical profiles of water temperature and chlorophyll-a. The ayu's echoes were identified using an underwater video camera. The ayu were observed near the maximum chlorophyll-a depth and above the thermocline. Their density was highest at depths of 4–11 m with 2–4 individuals/m ³ and was almost zero below 20 m. Echo signs were recorded as having a frequent duration of more than 1 h at night, whereas were of a shorter duration in the day. The fish stay in the epilimnion during the day without any clear vertical migration, but are distributed more uniformly at night. The advantages of remaining in the epilimnion are discussed in terms of food availability and predator avoidance.     

氮吸附法分析生物质焦孔隙结构

采用氮吸附法对4种生物质焦(稻壳、树叶、玉米秆、棉花秆)的孔隙结构进行测量,结果表明,不同种类焦样的比表面积和孔径分布有明显差别,树叶的比表面积最大,为242.21 m2·g-1,玉米秆的比表面积最小,为0.81 m2·g-1.850℃时,稻壳、树叶、玉米秆焦样的孔径分布曲线在微孔和中孔范围各有一个分布峰,而棉花秆焦样的孔径分布曲线只在中孔范围内出现一个分布峰.热解温度是影响孔隙结构的一个重要因素,在高温条件下,同步热解得到的焦样的比表面积较大,微孔较多.在本研究中,600℃、850℃的稻壳焦样和850℃的树叶焦样具有较大的比表面积,比较适合做吸附剂.     

抗虫杂交棉F1、F2代纤维品质的比较研究

2003年,在山东尹庄、江苏扬州、安徽宿松、湖北荆州、湖南长沙、湖南南县、湖南澧县等7个地点,对包括对照中29在内8个组合的F1、F2代共计16个材料进行纤维品质的比较研究,结果表明:抗虫杂交棉F1和F2代间除纤维长度达到显著差异外,其他7项指标差异均无显著,但F2代纤维品质变异范围增大,劣质纤维比例增加,优良纤维比例减少,从而出现纤维品质的衰退。     

Acclimation abilities of three tropical rainforest seedlings to an increase in light intensity

Current practices in many nurseries involve the germination of tropical rainforest seedlings in shaded conditions and transferral, at a later date, to environments with greater light intensities. Determination of the ability of these seedlings to acclimate to increased light intensities will allow seedling stock to be processed with maximum efficiency within the nursery. The acclimation abilities of three species, Agyrodendron actinophyllum, Cardwellia sublimis, and Flindersia brayleyana, commonly found in north Queensland's rainforests were investigated in this study. These particular species are highly valued for their cabinet timber qualities and are being reared in nurseries for use in reforestation trials and programs in north Queensland. Seedlings were initially raised in greenhouse conditions under two layers of shade cloth (16% of full sunlight) and then transferred into full sunlight at three different ages (3 weeks, 10 weeks, 14 weeks). Upon transfer, organ ratios and the direction of dry matter distribution was determined for each species and age group. Approximately 3 months after the seedlings were transferred, the acclimation ability of each species and age group was then determined. Dry matter distribution was found to change with age, irrespective of light environment. Individuals within a species with larger root systems and thicker or more dense leaves had a greater acclimation ability than those with smaller root systems and thinner or less dense leaves. Furthermore, individuals within a species whose dry matter distribution upon transfer was directed towards developing a large root system, and a small photosynthetic area and mass, had a greater acclimation ability than those whose dry matter distribution was directed away from such morphologies. Awareness of these relationships allows a better understanding of seedling response to gap formation in natural forests, and also allows plant nursery operators to make a more informed decision about when to move seedlings to environments with a higher light intensity.     

分散松香施胶剂性能影响因素的探讨

对逆转法制备分散松香施胶剂过程中的主要因素如乳化剂的种类及用量、马来松香加合物含量、搅拌转速、加料速度和乳化温度等系统地进行了探讨，提出了合理的工艺条件，并对实际生产中可能出现的问题及解决办法进行了阐述。     

波尔山羊杂交后代体尺、体重与肉用性能的相关性研究

本文利用 SPSS数据处理软件 (10 .0版 )统计分析了 2 3只 (约 8～ 9月龄 )波尔山羊与唐山奶山羊杂交后代公羊的体尺、体重和肉用性能。结果表明 :(1)波尔山羊与唐山奶山羊杂交 F1 代体尺、体重与肉用性能指标的变异程度大于 F2 代 ,其中宰前重、胴体重、净肉重和胸宽四项指标变异程度在 F1 和 F2 代中都很大 ;(2 )杂交 F1 代、F2 代各项指标 t检验结果 ,除胸宽外其余指标差异显著或极显著 ;(3 )波尔山羊杂交后代中胸宽与各项指标间相关不显著 ,宰前重、胴体重、净肉重与体尺指标相关显著或不显著。     

猪血浆转铁蛋白与部分经济性状关系的研究——Ⅰ. 多态性与产仔数和日增重的关系

用经改进的聚丙烯酰胺凝胶电泳铁染法,测定了二花脸猪血浆转铁蛋白多态类型,分析了其基因型频率和基因频率,并探讨了猪血浆转铁蛋白多态性与产仔性能和增重速度的相关性。